CREATE PROJECTION

Creates metadata for a projection in the Vertica catalog. Vertica supports four types of projections:

Standard projection: Stores collection of table data in a format that optimizes execution of certain queries on that table.
Live aggregate projection: Stores the grouped results of queries that invoke aggregate functions (such as SUM) on table columns.
Top-K projection: Stores the top k rows from partitions of selected rows.
UDTF projection: Stores newly-loaded data after it is transformed and/or aggregated by user-defined transformation functions (UDTFs).

Complex data types have additional restrictions when used within a projection:

Each projection must include at least one column that is a primitive type or native array.
An AS SELECT clause can use a complex-type column, but any other expression must be of a scalar type or native array.
The ORDER BY , PARTITION BY , and GROUP BY clauses cannot use complex types.
If a projection does not include an ORDER BY or segmentation clause, Vertica uses only the primitive columns from the select list to order or segment data.
Projection columns cannot be complex types returned from functions such as ARRAY_CAT .
TopK and UDTF projections do not support complex types.